Next-generation Sequencing: For the Present Generation Oncologist

Abstract

Previously, doctors had to treat this deadly disease based on immunohistochemistry, polymerase chain reaction and fluorescence in situ hybridisation-based diagnostics tests information which used to provide limited information. There was always a requirement of a single test/assay which could give all these information in a single assay and without much loss of precious sample. Comprehensive next-generation sequencing (NGS)-based assays are gaining much importance in treatment decision among clinicians. These present technologies using DNA, RNA, and methylation sequencing have brought a lot of changes in cancer therapeutics. Oncogenic drivers are genomic alteration lead to malignant transformation and progression of cancer. The interpretation of the results of NGS is also very challenging as the results obtained are ‘variants’ are of unknown prognostic significance. Apart from these, NGS helps us in documenting various other genomic signatures such as tumour mutation burden and microsatellite instability. There are now multiple gene panels that are recommended by major international societies such as NCCN, for the treatment of various malignancies. In fact, NGS forms the most important pillar of precision oncology and has brought a paradigm shift in the way major cancers are treated. It is still an evolving field and many times the interpretation of the results of NGS reports is very difficult. NGS-based precision medicine treatment offers true value addition in clinical practice has a positive impact on patient lives in cases of refractory cancer, the role of NGS is the only source of light that helps us in navigating amidst the darkness and hopelessness of a refractory malignancy. In fact, presently not only in refractory malignancies but the role of NGS has come in the management of cancer patients in the first line as it gives us a more comprehensive understanding of the disease. This review article has been written with an idea to make a general practitioner aware of this novel technique, the advantages as well as the pitfalls.